Sterile container

ABSTRACT

A sterile container is provided which may be used for receiving and storing surgical instruments or surgical material. The sterile container comprises a receiving space formed by a container bottom and container walls, a lid for closing the receiving space, and a sterile barrier comprising a first carrier and a second carrier facing the first carrier. The first carrier and the second carrier define a sterile flow path therebetween in the form of a Pasteurian loop which establishes a fluid connection between the receiving space and an environment outside the sterile container. One of the first carrier and the second carrier are movable relative to the other of the first carrier and second carrier from a sterile position defining the sterile flow path to a overpressure position defining an overpressure flow path in which the one carrier has moved away from the other carrier. In the overpressure position, a pressure difference between pressures prevailing in the receiving space and in the environment outside of the sterile container exceeds a minimum pressure difference.

This application is a continuation of commonly-owned co-pending U.S.patent application Ser. No. 11/543,463 filed on Oct. 3, 2006, which is acontinuation of international patent application numberPCT/EP2005/003843 filed on Apr. 12, 2005, and which claims the benefitof German patent application number 10 2004 020 804.2 filed on Apr. 16,2004, each of which is incorporated herein and made a part hereof byreference in their entirety and for all purposes.

BACKGROUND OF THE INVENTION

The invention relates to a sterile container, in particular, forreceiving and storing surgical instruments or surgical material understerile conditions, comprising a receiving space formed by a containerbottom and container walls, a lid for closing the receiving space, asterile barrier permanently defining a sterile flow path forestablishing a fluid connection between the receiving space and anenvironment outside of the sterile container, and an overpressure flowpath defining a fluid connection between the receiving space and theenvironment outside of the sterile container, wherein the overpressureflow path is closed when the sterile container is in a sterile positionin which an exchange of gas between the receiving space and theenvironment outside of the sterile container is only possible throughthe sterile flow path, and wherein the overpressure flow path is atleast partially open when the sterile container is in an overpressureposition in which a pressure difference between pressures prevailing inthe receiving space and in the environment outside of the sterilecontainer exceeds a minimum pressure difference.

Sterile containers of the kind described at the outset with sterilebarriers are used to enable exchange of fluid, i.e., exchange of gases,liquids or gas-liquid mixtures, for example, air, in particular, duringstorage of the sterile container, between the environment outside of thesterile container and the receiving space. During sterilization of thesterile container, large pressure differences between the environmentoutside of and the receiving space inside of the sterile container mayarise and cause damage to the sterile container by, for example, thesterile container being compressed or inflated by pressure forces actingthereon. To avoid damage, when a minimum pressure difference isexceeded, additional bypass flow paths are opened, which permit a highair mass exchange within a short time, which would not be possible viathe sterile flow path. As sterile barriers, there are known, on the onehand, filters made of porous material, through which germs and bacteriaare unable to pass, and, on the other hand, specially shaped flow paths,which do allow free passage of air, which, in principle, would alsopermit bacteria and germs to penetrate into the interior of thecontainer, but the aerodynamic conditions in these special flow pathsare configured such that there are areas where no flow occurs. Bacteriaand germs settle in these flow-free areas and, therefore, cannot enterthe receiving space of the sterile container.

In principle, it would be possible to provide a pressure relief valve onthe sterile container, which, in the event the minimum pressuredifference is exceeded, permits exchange of gas between the environmentoutside of and the receiving space inside of the sterile container. Forthis purpose, a further opening would, however, have to be provided inthe sterile container, and, in addition, such a pressure relief valvewould have to be serviced at regular intervals.

The object of the present invention is, therefore, to so improve asterile container of the kind described at the outset that design andmaintenance of the sterile container are particularly simple.

SUMMARY OF THE INVENTION

This object is accomplished, in accordance with the invention, in asterile container of the kind described at the outset in that a gas flowcross section of the sterile flow path is alterable for formation of theoverpressure flow path.

Accordingly, a sterile flow path that is unalterable in itsconfiguration is not provided, but rather a sterile flow path that has avariable flow cross section. When a minimum pressure difference betweenpressures prevailing in the environment outside of and in the receivingspace inside of the sterile container is exceeded, it is then possible,in a sterile container according to the invention, to alter, inparticular, to increase, the gas flow cross section of the sterile flowpath, so as to open up a bypass flow path for a gas exchange that isrequired to relieve the prevailing pressure difference. An overpressureflow path is thus formed by altering the gas flow cross section of thesterile flow path. In doing so, the sterile flow path could be separatefrom the overpressure flow path or in fluid communication therewith.

It is advantageous for the sterile flow path to have a first flow crosssection in the sterile position, for the sterile flow path to have asecond flow cross section in the overpressure position, and for theoverpressure flow path to have a third flow cross section, whichcorresponds to the difference between the first flow cross section andthe second flow cross section. In pure mathematical terms, this meansthat the overpressure flow path is obtained from a difference betweentwo different flow cross sections of the sterile flow path.

In particular, this is the case when the sterile flow path and theoverpressure flow path are in fluid communication with one another orthe overpressure flow path forms part of the increasing sterile flowpath. In particular, in the last-mentioned case, the design of thesterile container is significantly simplified because no additionalopenings need be provided on the sterile container.

The sterile barrier is particularly well protected against outsideinfluences when it is arranged on an inner side of the sterilecontainer.

A holding device is preferably provided for holding at least one part ofthe sterile barrier on the sterile container. This makes it possible toarrange the sterile barrier in a simple way on the sterile container,for example, to mount it thereon or connect it thereto.

In accordance with a preferred embodiment of the invention, it may beprovided that at least one part of the sterile barrier and the holdingdevice are releasably connectable, and that the at least one part of thesterile barrier is releasable from the holding device in a removeposition and is held on the holding device in a connect position. Thisallows at least one part of the sterile barrier to be released from thesterile container for cleaning purposes.

Advantageously, the sterile barrier is constructed in the form of aPasteurian loop (tortuous path), and the sterile flow path is ofmeander-shaped configuration. No consumables are needed for this kind ofsterile barrier, on the contrary, a Pasteurian loop (tortuous path) canbe cleaned in a simple way, sterilized and reused virtually as often asrequired.

It is advantageous for the Pasteurian loop (tortuous path) to comprise afirst carrier and a second carrier facing the first carrier, for thefirst carrier and the second carrier to each carry concentricring-shaped projections extending in the direction towards therespective other carrier, and for a ring-shaped projection of the onecarrier to respectively enter at least partially in between tworing-shaped projections of the other carrier in the sterile position.Owing to this configuration, a meander-shaped flow path is formed, i.e.,no straight-lined connection through the sterile barrier exists, so thatno straight-lined flow along the sterile flow path can be formed in thesterile position. Gas and particles, for example, germs and bacteria,contained therein are subjected to successive changes in direction whileflowing through the sterile flow path, and heavier particles collect inflow-free areas of the flow path.

A particularly simple configuration of the sterile flow path is obtainedwhen the ring-shaped projections of the one carrier have a wallthickness which is smaller than a spacing between adjacent ring-shapedprojections of the other carrier.

The ring-shaped projections of the two carriers advantageously have aheight which is smaller than a spacing of the two carriers from oneanother in the sterile position. It is thereby ensured that the sterileflow path is permanently open for gas exchange.

A particularly compact construction and a particularly simple design ofthe sterile barrier are obtained when the first carrier and the secondcarrier are arranged parallel or substantially parallel to one another.

A first gas flow cross section of the sterile flow path, which issufficient for gas exchange, is ensured when in the sterile position aspacing of the one carrier from the ring-shaped projections of the othercarrier is smaller than a height of the ring-shaped projections of theone carrier.

In order that a large air mass exchange can be ensured between theoutside environment and the interior of the sterile container, it isadvantageous for a spacing of the one carrier from the ring-shapedprojections of the other carrier to be greater than a height of thering-shaped projections of the one carrier in the overpressure position.

To reduce the number of movable parts, it is advantageous for one of thetwo carriers to be immovably connected to the sterile container.

A connection which may prove susceptible to failure can be dispensedwith when one of the two carriers is formed integrally with the sterilecontainer.

To establish a fluid connection with the environment outside of thesterile container, it is advantageous for one of the two carriers tohave a gas exchange opening which is in fluid communication with theenvironment outside of the sterile container, and for the ring-shapedprojections of one of the two carriers to concentrically surround thegas exchange opening. In particular, it is then only necessary for asingle opening to be provided on the sterile container, and this may besurrounded by structures of one part of the sterile barrier. Thisadditionally simplifies the design of the sterile container and thesterile barrier.

In order to enlarge a gas flow cross section of the sterile flow path ina particularly simple way, it is advantageous for the second carrier tobe mounted on the sterile container so as to be movable relative to thefirst carrier. With this configuration, an alteration in the gas flowcross section of the sterile flow path is achieved by the two carriersbeing moved relative to one another.

Advantageously, at least one stop is provided for specifying a minimumspacing between the first carrier and the second carrier. This preventsthe two carriers from approaching one another so far that a sterile flowpath is completely closed, which, in principle, is not, but, inexceptional cases, may be desired. Normally, however, the sterile flowpath is intended to be permanently open so as to allow permanent gasexchange between the environment outside of the sterile container andthe receiving space therein. In principle, it would be conceivable forthe first carrier to carry the at least one stop. It is, however,particularly advantageous for the second carrier to carry the at leastone stop. In particular, when the movably mounted carrier carries the atleast one stop, the stop can then be used for both guaranteeing aspacing between the two carriers and centering these relative to oneanother, which is particularly advantageous in the case of a sterilebarrier in the form of a Pasteurian loop (tortuous path).

The design of the sterile barrier becomes particularly simple when theat least one stop is constructed in the form of a projection, and when aheight of the projection corresponds to the minimum spacing between thefirst carrier and the second carrier. One of the two carriers may,therefore, come to rest directly on the stop.

A sterile container becomes particularly simple to manufacture when thesterile barrier and/or the gas exchange opening are of substantiallycircular design.

In order to hold the sterile barrier or at least one part thereof in asimple way on the sterile container, it may be advantageous for theholding device to comprise at least one holding element for holdingand/or supporting at least one part of the sterile barrier.

In accordance with a preferred embodiment of the invention, it may beprovided that the at least one holding element is mounted so as to bemovable on the sterile container. In particular, this allows at leastone part of the sterile barrier to be immovably connected to a holdingelement, so that the at least one part of the sterile barrier is thenstill mounted so as to be movable relative to the sterile container.

It is advantageous for the at least one holding element to be held in abiased manner on the sterile container, so that when a pressuredifference is smaller than the minimum pressure difference, the sterilecontainer will assume the sterile position. It is thereby ensured thatthe overpressure flow path will only be opened when it is reallyrequired, namely when the minimum pressure difference is exceeded.

In accordance with a further preferred embodiment of the invention, itmay be provided that the sterile barrier comprises at least one holdingportion, that the holding device comprises at least one holding element,and that the at least one holding portion is supported on the at leastone holding element. Thus, the sterile barrier or a part thereof can beheld in a defined manner on the sterile container, in particular,connected thereto or movably mounted thereon.

A particularly simple holding is made possible by the at least oneholding element comprising a holding arm which covers the holdingportion and is arranged so as to extend parallel or substantiallyparallel to a sterile container wall carrying the sterile barrier. Forexample, the holding portion can be held clamped against a wall of thesterile container by the holding arm in the closed position.

The at least one holding element advantageously extends over an angularrange in the circumferential direction of the sterile barrier. Thesterile barrier or a part thereof is thereby prevented from being ableto move in an undesired manner relative to the sterile container, inparticular, parallel to a wall thereof. The at least one holding elementthus also serves as a kind of centering device.

It is advantageous for the angular range to have values of from 10° to50°, in particular, 20°, so as to be able to use a plurality of holdingelements that are as small as possible.

In principle, it would be possible to provide a single holding element.However, a particularly secure holding of the sterile barrier on thesterile container is ensured when at least two holding elements areprovided, and when the at least two holding elements are arrangedsymmetrically around the sterile barrier. In particular, it isadvantageous for four holding elements to be arranged symmetricallyaround the sterile barrier.

In principle, it would be possible to arrange the sterile barrier on acontainer wall or on the container bottom. It is, however, particularlyeasily accessed, in particular, for cleaning purposes, when it isarranged on the lid.

In order that the sterile barrier and the objects accommodated in thereceiving space will not be destroyed when the overpressure flow path isopened abruptly, for example, due to unintentional release of a part ofthe sterile barrier from a holding device holding it, it may beadvantageous for at least one stop to be provided for delimiting amaximum gas flow cross section of the sterile flow path.

The sterile container is particularly light and easy to manufacture whenthe lid and/or the sterile barrier is/are made from a plastic material,in particular, from polyetheretherketone (PEEK) or polyphenylene sulfone(PPSU). It would also be conceivable to additionally reinforce theplastic material, for example, with glass fibers and/or carbon fibers.

It is advantageous when in the overpressure position the pressureprevailing in the environment outside of the sterile container exceedsthe pressure prevailing in the receiving space by at least the minimumpressure difference. This means that the overpressure flow path is atleast partially open when in the environment outside of the sterilecontainer a pressure prevails, which is greater than the pressureprevailing in the receiving space by at least the minimum pressuredifference. Accordingly, a pressure difference prevailing, for example,during sterilization of the sterile container can be reduced by at leastpartially opening the overpressure flow path and thereby allowing hotsteam to flow into the receiving space. The variable flow cross sectionthus makes it possible for a kind of pressure relief valve to be createdin the form of an inlet valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe appended drawing figures, wherein like reference numerals denotelike elements, and:

FIG. 1: a partly sectional view through a sterile container;

FIG. 2: an enlarged view of area A in FIG. 1 with a sterile barrier inthe sterile position;

FIG. 3: a view similar to FIG. 2 with the sterile barrier in theoverpressure position; and

FIG. 4: a perspective view of a movably mounted part of the sterilebarrier.

DETAILED DESCRIPTION

FIG. 1 shows a sterile container, generally designated by referencenumeral 10, which comprises a container tray 12 and a lid 14 for closingthe container tray 12. Surgical instruments and surgical material may,for example, be stored in an interior 16 of the sterile container 10.

The lid 14 has a vertically projecting, circumferential rim 18 and asomewhat shorter projection 20 extending parallel thereto. The rim 18and the projection 20 define between them a circumferential sealinggroove 22 in which a seal 24 is inserted. The sealing groove 22 servesto receive front edges 26 of walls 28 of the container tray 12. The seal24 comes to rest directly on the front edges 26 and is compressedsomewhat by two closure latches 30 arranged opposite one another on thelid 14, when locking the container tray 12, so that the lid 14 closesthe container tray 12 in a gas-tight manner.

A circular inlet opening 34 is provided in a lid wall 32 at the centerof the lid 14 and is surrounded by concentric ring projections 38extending vertically from an inner surface 36 of the lid wall 32. Thelid wall 32 thus forms a first carrier for the ring projections 38. Acarrier plate 40 in the form of a flat disc forms a second carrier.Concentric, ring-shaped projections 44 extend from a side surface 42,facing the inner surface 36, of the carrier plate 40. Their wallthickness is smaller than a spacing between adjacent projections 44. Awall thickness of the ring projections 38 is likewise smaller than aspacing between two adjacent ring projections 38.

The radii of the ring projections 38 and the projections 44 are selectedso that both the ring projections 38 and the projections 44 are alignedconcentrically, with a ring projection 38 entering partially between twoprojections 44 and a projection 44 between two ring projections 38,respectively.

Furthermore, four spacers 48 are arranged on the side surface 42adjacent a side edge 46 of the carrier plate 40 so as to project fromthe side surface 42. The spacers 48 are distributed uniformly over thecircumference of the carrier plate 40 and each extend over an angularrange 50 of approximately 20°. A height of the spacers 48, starting fromthe side surface 42, is both greater than a height 52 of the ringprojections 38, starting from the inner surface 36, and greater than aheight 56 of the projections 44, starting from the side surface 42.

The spacers 48, which bear against the inner surface 36, define aminimum spacing of the inner surface 36 from the side surface 42. Inthis sterile position, shown in FIGS. 1 and 2, a meander-shaped flowpath 58, indicated by a dotted line in FIG. 2, is thus formed. Itconnects the interior 16 of the sterile container 10 with an environment60 outside thereof. The meander-shaped flow path 58 is also referred toas Pasteurian loop (tortuous path) and exhibits a special effect, namelythat particles carried along in a flow of gas flowing along the flowpath 58, for example, germs and bacteria, collect in corners 62 in thearea of transition between the ring projections 38 and the inner surface36 and in corners 64 in the area of transition between the projections44 and the side surface 42 due to the absence of a flow in theaforementioned areas. Owing to the large number of windings in the flowpath 58 and, consequently, the large number of flow-free areas,particles carried along in the flow of gas are, so to speak, filteredout by deposition in the corners 62 and 64.

The carrier plate 40 is mounted by means of four identical holdingdevices 66 so as to be movable on the lid wall 32. Each of the holdingdevices 66 has a bearing pin 68 projecting perpendicularly from theinner surface 36. The bearing pin 68 is surrounded by a pot-shapedbearing element 72 having a bottom 74 bearing against the inner surface36. The bottom 74 has, in turn, a bore 76 which is somewhat larger indiameter than a diameter of the bearing pin 68. A terminating sleevewith a radially projecting ring flange 80 is positioned on the bearingpin 68. The diameter of the ring flange 80 corresponds approximately toan inner diameter of the bearing element 72. In this way, a ring space82 surrounding the bearing pin 68 is delimited by the ring flange 80 ofthe terminating sleeve 78 and by the bearing element 72. Inserted in thering space 82 is a helical spring 70 which is supported, on the onehand, on the ring flange 80 and, on the other hand, on the bottom 74 ofthe bearing element 72. Owing to this special arrangement, the bearingelement 72 is biased by the helical spring 70 in a normal positioncorresponding to the sterile position against the inner surface 36.

A bearing projection 84 extends transversely, i.e., parallel to theinner surface 36, from the bearing element 72, so that the bearingelement 72 forms together with the inner surface 36 a groove-shapedreceptacle 86 for mounting the carrier plate 40. The bearing projection84 bears against an underside 88 of the carrier plate 40. Owing to theaction of the helical spring 70, the bearing projection 84 is pressedagainst the underside 88, so that the carrier plate 40 bears with thespacers 48 against the inner surface 36 in the normal position.

In the normal or sterile position shown in FIG. 2, the flow path 58 hasa cross section designated 90. When the pressure in the environment 60outside of the sterile container 10 rises in relation to a pressure inthe interior 16, the carrier plate 40 is pressed against the bearingprojections 84, and the bottom of the bearing element 72 therebycompresses the helical spring 70 supported on the ring flange 80. Thiscauses a spacing between the side surface 42 and the inner surface 36 tobe increased, with the result that the flow path 58 has a cross section92, which is larger than the cross section 90. Owing to the increase inthe cross section 90 of the flow path 58, a straight-lined flow path 94is formed between the ring projections 38 and the projections 44, bymeans of which the excessive pressure difference can be reduced. Theflow path 94 thus forms an overpressure flow path. In this overpressureposition shown in FIG. 3, the effect of the Pasteurian loop (tortuouspath) owing to the meander-shaped flow path 58 is shut off. When thepressure acting on the carrier plate 40 drops again, the helical springs70 press the bearing elements 72 against the inner surface 36 again, sothat the sterile barrier formed by the carrier plate 40 together withthe ring projections 38 and the projections 44 is transferred again tothe sterile position shown in FIG. 2.

All of the elements of the lid are preferably made from a plasticmaterial, so that corrosion of the lid 14 is minimized.

On an outer side of the lid 14, a protective cover 96 is clipped in amanner not shown in greater detail onto the lid 14 so as to completelycover the inlet opening 34.

1. Sterile container, comprising: a receiving space formed by acontainer bottom and container walls; a lid for closing the receivingspace; a sterile barrier comprising a first carrier and a second carrierfacing the first carrier, the first carrier and the second carrierdefining a sterile flow path therebetween in the form of a Pasteurianloop which establishes a fluid connection between the receiving spaceand an environment outside the sterile container; one of the firstcarrier and the second carrier being movable relative to the other ofthe first carrier and second carrier from a sterile position definingthe sterile flow path to a overpressure position defining anoverpressure flow path in which the one carrier has moved away from theother carrier; wherein in the overpressure position a pressuredifference between pressures prevailing in the receiving space and inthe environment outside of the sterile container exceeds a minimumpressure difference.
 2. Sterile container in accordance with claim 1,wherein in the sterile position the sterile flow path has a first flowcross section, in the overpressure position the sterile flow path has asecond flow cross section, and the overpressure flow path has a thirdflow cross section, which corresponds to the difference between thefirst flow cross section and the second flow cross section.
 3. Sterilecontainer in accordance with claim 1, wherein the sterile barrier isarranged on an inner side of the sterile container.
 4. Sterile containerin accordance with claim 1, wherein a holding device is provided forholding at least one part of the sterile barrier on the sterilecontainer.
 5. Sterile container in accordance with claim 4, wherein theat least one part of the sterile barrier and the holding device arereleasably connectable, and the at least one part of the sterile barrieris releasable from the holding device in a remove position and is heldon the holding device in a connect position.
 6. Sterile container inaccordance with claim 1, wherein the first carrier and the secondcarrier each carry concentric ring-shaped projections which extend in adirection towards the respective other carrier, and in the sterileposition a ring-shaped projection of one carrier respectively enters atleast partially in between two ring-shaped projections of the othercarrier.
 7. Sterile container in accordance with claim 6, wherein thering-shaped projections of the one carrier have a wall thickness whichis smaller than a spacing between adjacent ring-shaped projections ofthe other carrier.
 8. Sterile container in accordance with claim 6,wherein the ring-shaped projections of the two carriers have a heightwhich is smaller than a spacing of the two carriers from one another inthe sterile position.
 9. Sterile container in accordance with claim 6,wherein the first carrier and the second carrier are arranged parallelor substantially parallel to one another.
 10. Sterile container inaccordance with claim 6, wherein in the sterile position a verticalspacing of the one carrier from the ring-shaped projections of the othercarrier is smaller than a height of the ring-shaped projections of theone carrier.
 11. Sterile container in accordance with claim 6, whereinin the overpressure position a vertical spacing of the one carrier fromthe ring-shaped projections of the other carrier is greater than aheight of the ring-shaped projections of the one carrier.
 12. Sterilecontainer in accordance with claim 6, wherein one of the two carriers isimmovably connected to the sterile container.
 13. Sterile container inaccordance with claim 12, wherein one of the two carriers is formedintegrally with the sterile container.
 14. Sterile container inaccordance with claim 6, wherein: one of the two carriers has a gasexchange opening which is in fluid communication with the environmentoutside the container, and the ring-shaped projections of one of the twocarriers concentrically surround the gas exchange opening.
 15. Sterilecontainer in accordance with claim 6, wherein the second carrier ismounted on the sterile container so as to be movable relative to thefirst carrier.
 16. Sterile container in accordance with claim 6, whereinat least one stop is provided for specifying a minimum spacing betweenthe first and the second carriers.
 17. Sterile container in accordancewith claim 1, wherein: the sterile barrier and/or a gas exchange openingwhich is in fluid communication with the environment outside of thesterile container is/are of circular or substantially circularconstruction.
 18. Sterile container in accordance with claim 4, whereinthe holding device comprises at least one holding element for holdingand/or supporting at least one part of the sterile barrier.
 19. Sterilecontainer in accordance with claim 18, wherein the at least one holdingelement is mounted so as to be movable on the sterile container. 20.Sterile container in accordance with claim 18, wherein the at least oneholding element is held in a biased manner on the sterile container, sothat the sterile container will assume the sterile position when thepressure difference is smaller than the minimum pressure difference. 21.Sterile container in accordance with claim 4, wherein the sterilebarrier comprises at least one holding portion, the holding devicecomprises at least one holding element, and the at least one holdingportion is supported on the at least one holding element.
 22. Sterilecontainer in accordance with claim 1, wherein the sterile barrier isarranged on the lid.
 23. Sterile container in accordance with claim 1,wherein at least one stop is provided for delimiting a maximum gas flowcross section of the sterile flow path.
 24. Sterile container inaccordance with claim 1, wherein the lid and/or the sterile barrieris/are made from a plastic material, in particular, frompolyetheretherketone (PEEK) or polyphenylene sulfone (PPSU).
 25. Sterilecontainer in accordance with claim 1, wherein in the overpressureposition the pressure prevailing in the environment outside of thesterile container exceeds the pressure prevailing in the receiving spaceby at least the minimum pressure difference.